                                                           :Instruments [i1 i2]
                                                           :Characteristics [c1 c2]})]}))
       (h/assert-valid (coll/map->UMM-C
-                       {:Platforms [(c/map->PlatformType {:ShortName "P1"
+                       {:Platforms [(c/map->PlatformType {:ShortName "DHC-6"
                                                           :Characteristics [c3]})
-                                    (c/map->PlatformType {:ShortName "P1"
+                                    (c/map->PlatformType {:ShortName "DHC-6"
                                                           :Characteristics [c4]})]})))
 
     (testing "invalid platforms"

            ["Platforms must be unique. The combination of platform ShortName with Characteristics Name and Value contain duplicates named [P1]."])))
      (testing "duplicate platform short names with characteristics"
        (let [coll (coll/map->UMM-C
                     {:Platforms [(c/map->PlatformType {:ShortName "P1"
                                                        :Characteristics [c3]})
                                  (c/map->PlatformType {:ShortName "P1"
                                                        :Characteristics [c3]})]})]
          (h/assert-invalid
            coll
            [:Platforms]
            ["Platforms must be unique. The combination of platform ShortName with Characteristics Name and Value contain duplicates named [P1C3C3]."])))
      (testing "duplicate platform characteristics names"
        (let [coll (coll/map->UMM-C
                     {:Platforms [(c/map->PlatformType {:ShortName "P1"

                                   :ComposedOf [s1 s2]})
        c1 (c/map->CharacteristicType {:Name "C1"})
        c2 (c/map->CharacteristicType {:Name "C2"})
        c3 (c/map->CharacteristicType {:Name "AircraftID"
                                       :Value "C-FSJB"})
        c4 (c/map->CharacteristicType {:Name "AircraftID"
                                       :Value "N572AR"})]
    (testing "valid platforms"
      (h/assert-valid (coll/map->UMM-C
                       {:Platforms [(c/map->PlatformType {:ShortName "P1"
